Definition of "vernier" in English

noun

1. A secondary scale with finer graduations than the primary scale of a measuring device; the vernier measures between graduations of the larger scale.

2. A secondary control input with finer control than the primary, or coarse, input; for example the vernier frequency tuning knob on a radio.

3. (physics) A secondary system of force application for the attitude control of a spacecraft; for example a vernier thruster.